THOUSAND-LAYER CHOCOLATE CHIP COOKIES

Steps:

• In a medium bowl, whisk the flour, baking soda and salt together. In the bowl of a stand mixer fitted with the paddle attachment, cream the butter and both sugars on medium speed until light and fluffy, about 3-4 minutes, stopping to scrape down the sides of the bowl once or twice. Add the egg yolks, two at a time, beating until combined, then add the vanilla. With the mixer on low, gradually add the dry ingredients, beating just until incorporated. Divide the dough into three equal portions. Shape each into a 4x6-inch rectangle, then wrap in plastic wrap and refrigerate for at least 30 minutes. Unwrap the dough rectangles. Place one on a lightly floured work surface. Sprinkle half of the chocolate evenly over the dough rectangle. Top with a second piece of dough. Sprinkle the remaining chocolate over the second piece of dough, then finally top with the third piece of dough. The tower of dough and chocolate will be tall, and chocolate may fall out the sides, that's ok. Dust the top piece of dough lightly with flour, then use a rolling pin to gently roll the stack of dough and chocolate into roughly a 9x6-inch rectangle about 1 1/2 inches thick. Use a 2-inch round cutter to cut as many rounds as possible from the dough. Transfer the rounds to a parchment-lined baking sheet. Gather the scraps of dough together into a 1 1/2-inch thick mound and cut additional cookies out. Cover the baking sheet loosely with plastic wrap and refrigerate the unbaked cookies for at least an hour or two. Preheat oven to 375 F. If you're going to bake all of the cookies at once, separate them onto a few baking sheets, leaving at least 2-3 inches between the rounds (the cookies will spread a lot). Brush the tops of the rounds with the egg wash and, if desired, sprinkle with a few grains of fleur de sel. Bake for 14-15 minutes, or until the edges of the cookies are set